Method and apparatus for harvesting trees

ABSTRACT

A novel combination delimber and top shear utilized as an integral part of tree harvester. The tree harvester incorporating the delimber and top shear unit of this invention includes a horizontally oriented mast which is mounted on a mobile vehicle. A butt shear and felling grapple are pivotally mounted at one end of the mast and are adapted to grasp and sever a standing tree and pivot it to a substantially horizontal position overlying the mast where it is grasped and securely held by a transfer grapple. The novel combination delimber and top shear unit, which includes a pair of delimber arms and a pair of top shear blades, is mounted for longitudinal movement on the top of the mast and is adapted to be driven along the tree to strip all limbs from the tree and also to remove the top portion of the tree at either a predetermined length or diameter. After the tree has been delimbed and topped, it is dropped by the transfer grapple into collection arms positioned at intervals along the mast and adapted to hold a large number of delimbed and topped trees to be transported by the tree harvester to a collection point where the trees are deposited in a stack.

[ 1 May 22, 1973 United States Patent 1 Shields [57] ABSTRACT A novelcombination delimber and top shear utilized R 0 F S U T M m E R T 6 N mD 0% RV TR A MH m [75] Inventor: Dean W. Shields, Toledo, Ohio as anintegral part of tree harvester. The tree harvester [73] Assignee:Owens-Illinois, Inc., Toledo, Ohio incorporating the delimber and topshear unit of this invention includes a horizontally oriented mast whichis mounted on a mobile vehicle. A butt shear and felling grapple arepivotally mounted at one end of the [22] Filed: Dec. 24, 1969 [2]] Appl.No.: 887,903

mast and are adapted to grasp and sever a standing tree and pivot it toa substantially horizontal position overlying the mast where it isgrasped and securely held by a transfer grapple. The novel combinationdelimber and top shear unit, which includes a pair of delimber arms anda pair of top shear blades, is mounted for longitudinal movement on thetop of the mast and ZM C 2/ A /34 w A DM 4 m n 4 m J W4 in "mm L C d Stfl ui. Ur -F 1]] 2 00 555 is adapted to be driven along the tree tostrip all limbs from the tree and also to remove the top portion of thetree at either a predetermined length or diameter. After the tree hasbeen delimbed and topped, it is dropped by the transfer grapple intocollection arms [56] References Cited UNITED STATES PATENTS 144/3 D Zpositioned at intervals along the mast and adapted to 8/1969Larson..................................144/3D l ma 9 me nn 00 BE aa LL56 66 99 11 l/ 53 1.1 582 1 1 38 836 333 hold a large number of delimbedand topped trees to be transported by the tree harvester to a collectionPr'mary ExammerGerald Dost point where the trees are deposited in astack. Attorney-E. J. Holler and Alan J. Steger 20 Claims, 13 DrawingFigures PAIENI M22 1975 SHEET 01 0F 11 irr m/ryr PATENTEU M219153.734152 I sum 02 HF 11 I NVEN TOR. Da A/JQ/zz or PATENTED M 2 19731,734,152

sum on HF 11 l NVENTOR.

PATENIE HAYZZ m3 SHEET C F) UE PATENTED HAYZ 21973 SHUT 1.1 U?

1 METHOD AND APPARATUS FOR HARVESTING TREES BACKGROUND OF THE INVENTIONThis invention relates to a novel method and apparatus for harvestingand processing trees.

More specifically, this invention relates to a novel combinationdelimber and top shear which is adapted to be driven along a tree tostrip all limbs from the tree and also to remove the top portion of thetree at either a predetermined length or diameter. This combinationdelimber and top shear is well suited to be utilized as an integral partof a. tree harvesting apparatus such as that disclosed in copending U.S.Ser. No. 887,937 filed Nov. 19,1969 and now U.S. Pat. No. 3,618,647 andassigned to the same assignee as the subject invention.

Historically, trees have been harvested by methods requiring varioussequences of operations and the use of a number of different tools,tractors, horses, saws, skidders, trucks, cranes and the like. Morespecifically, trees have been felled by using hand saws manually,manipulated power saws, axes, wedges and guide ropes. These proceduresobviously require a considerable amount of manual labor. In order toreduce the amount and cost of the manual labor various machines havebeen proposed heretofore for felling trees, but such machines have notbeen found to be sufficiently practical for harvesting trees from aforest. N

It is, therefore, an object of this invention to piovide a treeharvesting machine incorporating a unique combination delimber and topshear mechanism which completely processes a tree and overcomes thedisadvantages associated with previously known tree harvestingmachinery.

SUMMARY OF THE INVENTION This invention provides a novel combinationdelimber and top shear utilized as an integral part of a tree harvestingmachine which will cut, delimb, top, transport and deposit a pluralityof trees in a stack at a desired collection point.

In general, the tree harvesting machine of this invention includes asubstantially-horizontally extending mast which is mounted on a mobilevehicle. A butt shear and felling grapple are pivotally mounted at oneend of the mast and are adapted to grasp and sever a standing tree andpivot it to a substantially horizontal position overlying the mast. Atransfer grapple is mounted on the mast at the same end as the buttshear and felling grapple and is adapted to receive and securely holdthe tree after it has been laid down by the felling grapple. The novelcombination delimber and top shear of this invention is mounted forlongitudinal movement on the top of the horizontal mast and is adaptedto be driven along the tree to strip all limbs from the tree and toremove the top portion of the tree at either a predetermined length orpredetermined diameter. A plurality of tree collection arms are attachedto one side of the horizontal mast and are adapted to receive a largenumber of delimbed and topped trees to be transported by the treeharvester to a collection point where the trees can be dropped in abundle.

Other objects, features and advantages of this invention will becomeobvious upon reference to the following detailed description of theinvention and the drawings illustrating the preferred embodimentthereof.

IN THE DRAWINGS FIG. I is a perspective view of the tree harvester ofthis invention holding several processed trees to be transported withthe harvester and grasping a new standing tree to be processed.

FIG. 2 is a perspective view of the novel combination delimber and topshear unit utilized in the tree harvester of this invention.

FIG. 3 is an end view with parts broken away in section of thecombination delimber and top shear unit of FIG. 2 showing the unit inthe open or tree receiving position.

FIG. 4 is an end view with parts broken away in section of thecombination delimber and top shear unit of FIG. 3 showing theprogressive radial movement of the delimber arms (from solid lines todash-dot-dot lines to dash-dot lines) as the unit moves along a treefrom the base or large diameter end of the tree toward the top or smalldiameter end of the tree.

FIG. 5 is a side elevational view of the combination delimber and topshear unit of FIG. 2 showing the delimber closed around the tree and thetop shear blade open.

FIG. 6 is a top view with parts broken away in section of thecombination delimber and top shear unit of FIG. 5 showing the openingand closing apparatus for the delimber arms and top shear blades.

FIG. 7 is an enlarged sectional view of the combination delimber and topshear unit of FIG. 6 showing the opening and closing apparatus after ithas been actuated to close the top shears.

FIG. 8 is an enlarged sectional view of the combination delimber and topshear unit of FIG. 7 showing the opening and closing apparatus after ithas been actuated to open the delimber arms and the top shear blades.

FIG. 9 is a side elevational view of combination delimber and top shearunit of FIG. 8.

FIG. 10 is a sectional view of an actuating cylinder and mounting shaftutilized in connection with each delimber arm as shown in FIG. 5.

FIG. 11 is a cross-sectional view of the actuating cylinder taken in thedirection of lines A-A in FIG. 10.

FIG. 12 is a developed length view of a portion of FIG. 11.

FIG. 13 is an end view of the actuating cylinder taken in the directionof lines B-B in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION A tree harvester of which thenovel combination delimber and top shear of this invention is anintegral part is shown in FIG. 1 and is indicated generally by thenumeral 10. A mobile vehicle supporting and powering the tree harvestingapparatus of this invention is indicated generally by the numeral 12 andmay comprise any mobile vehicle such as a crawler tractor having aswingable base platform 14, power plant units 16, 17 and 18, operatorcab 20, and endless treads 22. The mobile vehicle 12 may be of anysuitable type which is adapted to support the tree harvester apparatusand convey it into a forest type area. In addition, the power plantunits 16, 17 and 18 may be of any standard type suitable to propel thevehicle 17. and to provide power for operating the various .treeharvesting apparatus which is hereinafter described.

The main structural component of the tree harvesting apparatus is a mast24 which is telescopingly mounted in a generally horizontal positionwithin a mast collar 26. The mast collar 26 is pivotally mounted aboveand supported on the base platform 14 by means of a mounting flange 28.A hydraulic actuating mechanism (not shown) is mounted between the baseplatform 14 and the mast collar 26 to control the vertical position ofthe mast 24. The mast 24 is adapted for linear movement relative to themast collar 26 and driven by means not shown. Thus, it should beunderstood that the position of the mast 24 may be controlled both tomove the mast into and away from the mobile power unit 12 and also tochange the angle of the mast 24 with respect to the horizon.

Pivotally mounted at one end of the mast 24 is a felling grapple unit 32which includes a butt shear mechanism 34 and four grasping arms 36. Thebutt shear 34 includes a pair of shearing blades 38, each of which areactuated for movement relative to the felling grapple unit 32 by meansof a hydraulic cylinder 40 (only one is visible in FIG. 1). The blades38 are adapted to completely sever the trunk of a tree when actuated bythe cylinders 40. The four grasping arms 36 securely hold and positionthe trunk of a tree while the cutting blades 38 of the butt shear 34sever the tree at a location close to ground level. The felling grappleunit 32 is actuatable to pivot 90 relative to the mast 24 by means of ahydraulic cylinder 44. Thus, once the butt shear 34 has severed a tree(such as the large standing tree 42 in FIG. 1) the cylinder 44 isactuated to pivot the felling grapple unit 32 and the tree 42 to ahorizontal position parallel to the mast 24.

Fixed to the top of the mast 24 at the same end as the felling grappleunit 32 is a transfer grapple unit 46. The transfer grapple unit 46includes four grasping arms 48 which are very similar to the graspingarms 36 on the felling grapple unit 32. It is the function of thegrasping arms 48 on the transfer grapple 46 to securely hold andposition the tree in an overlying position with respect to the mast 24while the delimbing and topping functions are performed by the novelapparatus of this invention to be described hereinafter. When the tree42 has been pivoted by means of the felling grapple unit 32 to aposition overlying the mast 24, the grasping arms 48 of the transfergrapple 46 are closed to grasp and securely hold the tree 42. At thistime, the arms 36 may be opened and the felling grapple unit 32 pivoteddownwardly 90 to its original position in preparation for grasping andsevering another tree.

The main feature of this invention, a combination delimber and top shearunit (hereinafter referred to as the unit), is indicated generally bythe numeral 50. The unit 50 includes both delimbing and toppingapparatus and is mounted on and adapted for longitudinal movement alongthe mast 24. The main frame of the unit 50 comprises a pair of sidemembers 52 which are connected by lateral support members 54. Thelateral support members 54 terminate at their upper extremities insemicircular tree receiving and supporting cradles 56. The unit 50 isadapted for longitudinal movement on the upper surface of the mast frame24 by means of rollers 58 and 60. The rollers 58 and 60 are mounted forrotation on shafts 62 and 64, respectively, which are supported withinside members 52. As can best be seen in FIG. 3, the larger rollers 58are positioned to roll along the top surface of the mast frame 24 andthe smaller rollers 60 are positioned to act as stabilizers on the lowersurface of the mast frame 24. The mast frame 24 is strengthened by beingintegral with a V-shaped support channel 66.

The unit 50 is moved along the mast frame 24 by means of a cable 68which is pulled around pulleys 70 on the mast 24 by means of a cabledrive device 72. The cable 68 is securely attached to a-cable hitch 74which in turn is secured to the side members 52 of the unit 50 by meansof retainer blocks 76 and bolts 78.

The novel delimber and top shear unit 50 of this invention includes apair of curved delimber arms 80 and 82, each of which has a cuttingblade 84 on its interior arcuate edge. The delimber arms 80 and 82 areeach mounted for rotational movement on a shaft and are normally springbiased into the closed position around the circumference of a tree asshown by the dash-dot lines in FIG. 3. Delimber arm 80 is mounted onshaft 86 which is biased by a spring contained within a cylinder 88.Similarly, delimber arm 82 is mounted on a shaft 90 which is biased by aspring housed within a cylinder 92. The respective shafts and actuatingcylinders for the delimber arms 80 and 82 are identical so that thefollowing description of the shaft 86 and cylinder 88, as appears inFIGS. 10 through 13, is also applicable to shaft 90 and cylinder 92.

In FIG. 10, it can be seen that the delimber arm 80 is keyed to shaft 86by means of a key 94. A piston 96 fits the walls of cylinder 88 and ismounted over a rod 98 which is rigidly fastened to an end portion 100 ofthe cylinder 88. The piston 96 includes a hollow cylindrical portion 102which fits snugly over the rod 98 and is closed at one end 104. The rod98 includes an axial opening 106 along its entire length which may beclosed by means of a plug 108. Thus, as the piston 96 is moved to theright, away from the fixed rod 98, a chamber is formed within the hollowcylinder portion 102 of the piston 96 between the rod 98 and the end 104of the piston 96. This chamber 110 is adapted to receive fluid throughthe opening 106 in the rod 98. As a fluid (such as grease, for example)is injected into the chamber 110 the piston 96 is forced to move awayfrom the rod 98.

The shaft 86 enters the cylinder 88 through opening 111 and is heldtherein by a thrust bearing 112 which bears against a clutch plate 114on the interior end of shaft 86. A second clutch plate 116 is mountedadjacent to the first clutch plate 114 within cylinder 88. As can bestbe seen in FIGS. 11 and 12, the matching clutch plates 114 and 116 eachhave a plurality of mating grooves 118 which coact to form an annularinclined plane therebetween. A plurality of spherical balls 120 arepositioned between the plates 114 and 116 within the grooves 118. Alarge coil spring 122 is mounted within the cylinder 88 and fastened atits opposite ends to the piston 96 at 124 and to the clutch plate 116 at126. The spring 122 is prevented from rotating by means of a latch bar128 which is fixed to the spring 122 and the piston 96 and restrictedwithin a keyway 130 in the cylinder 88.

Thus, it should be understood that as grease is introduced into thechamber 110, the piston 96 is forced to travel in a direction to theright in FIG. 10, thereby compressing the spring 122 against the clutchplate 116. The force of spring 122 on clutch plate 116 causes the balls120 in the inclined annular plane formed by grooves 118 to impart arotation to the clutch plate 114 and shaft to thereby bias the delimberarm 80 into engagement with a tree to be delimbed. In order to move thedelimber arm 80 outwardly (to the open position), clutch plate 114rotates against the balls 120 which must push the clutch plate 116 inthe axial direction against the force of spring 122. Thus, delimber arm80 is normally spring biased inwardly and can be moved to the openposition only by overcoming the biasing force of spring 122. The amountof force applied by the spring 122 may be controlled by adjusting theposition of piston 96 through the amount of grease introduced into thechamber 110. It should be noted further that the shaft 86 is positionedat its other end within a hearing 132 which is attached to the sidemember 52 by means of bolts 134. It should be understood that themounting and biasing apparatus for delimber arm 82 is identical to thatdescribed in connection with delimber arm 80. Also, cylinder 88 isattached to side member 52 by means of bolts 135.

Another integral part of the unit 50 is a top shear mechanism whichcomprises a pair of knife edge blades 136 which are actuatable to shearthrough a tree trunk at either a predetermined length of the tree of ata predetermined diameter to thereby remove the top portion of the tree.The top shear blades 136 are mounted on a pair of timing gears 138 whichhave meshing teeth 140. Both the top shear blades 136 and the timinggears 138 are mounted for rotation on a pair of pivot posts 142. Thetiming gears 138 are each connected to a floating block 144 by means ofa pair of connecting arms 146 as can be seen in FIGS. 7 and 8. Thefloating block 144 is mounted for rectilinear movement on a rectangularbeam 148 and is biased towards the delimber arms (tending to close thetop shear blades 136) v by means of a tension spring 150. The topcutting blades 136 are held in the open position (as shown in FIGS. 8and 9) by means of a latch 152 which is pivotally attached to a pair oftrigger arms 154 and 155. The latch 152 abuts a corner of the floatingblock 144 to fix the position of the connecting arms 146 and maintainthe top cutting blades 146 in the open position.

The operation of the delimbing arms and top shear can best be understoodby concentrating on the appa ratus shown in FIGS. 6 through 9. In FIG.8, it can be seen that an actuating plate 156 is provided to rotateabout a pivot 158. The actuating plate 156 is circular and has attachedthereto and wrapped around a portion of its circumference a pair ofdelimber arm cables 160 and 162. The delimber arm cable 160 is attachedto the circumference of the actuating plate 156 at one end by means ofbolt 164. The cable 160 is connected at its other end to acounter-balance plate 166 which is connected to the delimber arm 80 andpivots with the delimber arm 80 about shaft 86. Similarly, the delimberarm cable 162 is attached to the actuating plate 156 at one end by meansof bolt 170. Likewise, cable 162 is attached at its opposite end to acounter-balance plate 172 which is connected to the delimber arm 82 androtates about the shaft 90. Attached to the actuating plate 156 by meansof a pin 174 is a cam follower 176. The cam follower 176 is adapted toengage and follow a cam 178 which is positioned on the mast 24 at alocation near the front end of the tree harvester (adjacent the transfergrapple 46). A pin 180 is attached at one end to the actuating plate 156and at its other end resides within a lost motion slot 182 near one endof top shear opening bar 184. The top shear opening bar 184 is attachedat its other end by means of pin 185 to one of the timing gears 138.

To understand the initial operation of the unit 50 ref erence should behad to FIG. 8. In FIG. 8, the unit 50 is positioned adjacent to thetransfer grapple 46 and the delimber arms and 82 and the top shearblades 136 are in the open position and adapted to receive a tree. Afterthe unit 50 has received a f elled tree and moves away from the transfergrapple 46 (to the right in FIG. 8), the cam follower 176 follows theincline of cam 178 thereby rotating the actuating plate 156 in theclockwise direction. This clockwise rotation of the actuating plate 156then forces the delimber arm cables and 162 to be peeled off or payedout from the actuating plate 156 thereby allowing the actuating springs122 to spring bias the delimber arms into contact with the tree trunk42a (in FIG. 4). Simultaneously, pin moves within the lost motion 182and does not move the top shear opening bar 184. In the meantime, thelatch 152 remains in contact with the floating block 144 to maintain thetop shear blades 136 in the open position. As shown in FIG. 4, while theunit 50 proceeds along the trunk of the tree from the thick portiondesignated 42a to the narrow portion designated 42b, the delimber arms80 and 82 are spring biased radially inward to remain in contact withthe tree. This is illustrated in FIG. 4 by the transition from theposition shown in full lines to that shown in dash-dot-dot lines and tothat shown in dash-dot lines.

The apparatus will maintain the position shown in FIG. 6 until either apredetermined diameter of the tree or a predetermined length is reached.If it is desired to actuate the top shears 136 to top the tree at agiven diameter, a diameter sensing means 186 is provided. This diametersensing means includes a connecting rod 188 which is fastened at one endto the trigger 155 and to a pin 190 at its other end. The pin 190resides in a lost motion slot 192 in the counter-balance plate 166 whichrotates with the delimber arm 80. Thus, as the delimber arms moveradially inward, the pin 190 moves along the slot 192 until it abuts theend thereof at which point it moves with the counter-balance plate 166to pivot the trigger 154 and about its pivot point 196 to release thelatch 152 from the floating block 144. Once the latch 152 is released,the floating block 144 is allowed to move along slot 148 under theaction of spring 150 to thereby close the top shears 1.36 and top thetree. It should be noted that timing gears 138 with meshing teeth 140are utilized so that the movement and force of the two cutting blades136 are equal. Therefore, it can be seen that once the delimber arms 80and 82 have pivoted radially inward as they follow the tree trunk to apoint where a given minimum diameter is reached, the connecting rod 188is actuatedto release latch 152 and allow the top shear blades 136 tosnap radially inwardly to top the tree.

If, however, it is not desired to top the tree at a given minimumdiameter or, if the predetermined minimum diameter desired is notreached as the unit travels along the tree, a top shear actuatingmechanism is provided to close the top shears at a predetermined length.In FIG. 7, it can be seen that a top shear release cam 198 is providedon the mast frame 24 at a predetermined distance from the transfergrapple 46. For example, if it is desired to top all trees at a lengthno greater than 65 feet, the can 198 would be located at a predeter'mined distance from the transfer grapple 46 (such as 60 feet dependingon the exact position that the transfer grapple 46 grabs the tree whenreceiving it from the felling grapple 32) so that the desired result canbe accomplished. As can be seen in FIG. 7, a connecting arm 200 isattached to the trigger 154. This connecting arm 200 is attached at itsopposite end to a cam follower arm 202. The cam follower arm 202 ispivoted about a fixed pivot 204 at one end and has a cam follower 206 atits other end. This cam follower 206 is adapted to engage the cam 198 asthe unit 50 reaches the longitudinal location of the cam 198 on the mastframe 24. As can be seen in the transition from FIG. 8 to 7, the pivotarms 202 are pivoted downwardly as the cam follower follows the inclinedsurface of the cam 198 to pivot the trigger 154 against its retainingspring 194 about its pivot point 196 to thereby release the latch 152.As previously described when the latch 152 releases the floating block144, the cutting blades 136 are allowed to snap into the closed positionas shown in FIG. 7.

After the delimbing arms 80 and 82 have removed all branches from a treeand the topping shears 136 have topped the tree either at apredetermined diameter or length, the unit 50 moves on past the tree tothe end of the mast 24. When it reaches the end of the mast 24, thecable drive device 72 reverses the direction of cable 68 to return theunit 50 to a position adjacent to the transfer grapple 46. As wasdescribed in the abovedescribed co-pending application, after the unit50 has delimbed and topped a tree, the transfer grapple 46 is actuatedto drop the tree into a plurality of collection arms 208 which arefastened to one side of the mast frame 24. These collection arms 208 arecapable of holding a number of delimbed and topped trees fortransportation with the tree harvester 10. Additionally, the collectionarms are adapted to pivot downwardly to simultaneously drop a bundle ofprocessed trees at a predetermined collection point.

As the unit 50 traverses its return path adjacent to the transfergrapple 46, the mechanism retains its position shown in FIG. 7 and boththe delimber arms 80 and 82 and the top shear blades 136 remain in theclosed position. As the unit 50 approaches the transfer grapple 46 itagain encounters the cam 178 as shown in FIG. 8. While the unit 50 movesfrom right to left in FIG. 8, the cam follower 174 moves along theinclined surface of the earn 178 thereby rotating the actuating plate inthe counterclockwise direction. This rotation of the actuating plate 156causes the delimber arm cables 160 and 162 to be pulled towards andwound around the actuating plate 156. This retraction of the cables 160and 162 causes a rotation of the delimber arms 80 and 82 against theforce of their respective biasing springs (shown in FIGS. 10 through 13)so as to move the delimber arms to the open position (as shown in FIG.3). Likewise, as the actuating plate 156 rotates counterclockwise, thepin 180 pushes the top shear opening bar 184 in a direction towards theright in FIG. 8 thereby rotating the timing gears 138 to open the topshear blades 136. As the timing gears are rotated, the connecting arms146 pull the floating block 144 along the rectangular beam 148 againstthe force of spring 150 to a point where the latch 152 snaps in behindthe floating block 144 under the action of spring 194 on trigger 154.Thus, the effect of cam 178 on cam follower 176 and the subsequentrotation of actuating plate 156 as the unit 50 returns to a positionadjacent to the transfer grapple 46 results in the opening of both thedelimber arms and 82 and the top shear blades 136. The unit 50 thenassumes the position shown in FIG. 3 and is ready to receive anothertree for delimbing and topping.

Thus, the tree harvesting butt of this invention provides a treeharvesting machine which is capable of completely processing a pluralityof trees and delivering them as a group to a predetermined collectionpoint. Once the operator has directed the equipment to a given tree suchthat it has been grasped by the felling grapple unit 32 and severed bythe but shear device 34, the tree is then automatically pivoted to asubstantially horizontal position where it is grasped and held above themast 24 by the grasping arms 48 on the transfer grapple 46. The delimberarms 80 and 82 are then closed into contact with the tree 42 and thedelimber unit 50 is driven along the mast 24 and to remove all limbsfrom the tree. Once the delimber unit 50 reaches either a predeterminedlength or a predetermined diameter, as described previously, the topshears 136 are automatically closed to remove the top of the tree. Thedelimber unit 50 is then moved past the tree and the tree is released bythe arms 48 and dropped into the collection arms 66. It should be notedthat as soon as the tree is grasped and held by the arms 48 on thetransfer grapple 46, the felling grapple unit 32 is rotated back to itsinitial position and the operator may proceed to adjust the position ofthe mast 24 so that the felling grapple unit 32 is positioned to grab asecond tree while the first tree is being delimbed and topped. As soonas the first tree has been released by the holding arms 48 into thecollection arms 66, a second tree may be sheared by the butt shear 34and pivoted into position to be held by the arms 48 for delimbing andtopping. Thus, while one tree is being processed the operator mayposition the equipment to grasp and shear the next tree so that theharvesting process becomes a continuous one.

Therefore, it should be clear that a continuous tree harvester isprovided by this invention which is adapted to completely process treesin an extremely fast and economical manner. Previously, such treeharvesters have been adapted to sever and delimb only one tree at a timeprior to approaching a second tree. In addition, they were not equippedto stack and carry a number of processed trees for dumping in a bundleat a predetermined collection point. In other words, previous suchharvesters would process one tree at a time and drop it individually onthe ground for collection at a later time. This, therefore, required theuse of a separate tree gathering machine. In contrast to this, the noveltree harvester of this invention is capable of collecting on the machinea plurality of trees for transport with the machine and then dumpingthem in a group at a predetermined collection point. Thus, thisselftransporting feature of the subject invention eliminates the needfor a tree collection machine to be used for collecting individual treesdeposited randomly throughout the forest.

The harvester of this invention is completely mobile in that it issupported on and powered by a tractor type vehicle which is adapted fortravel over the rough terrain that is usually encountered in and arounda forest. Also, because of the maneuverability of its horizontal mastthe tree harvester of this invention is capable of reaching andprocessing a number of trees without changing the position of the maintractor support unit.

Additionally, the novel tree harvester of the subject invention requiredthe labor of only one operator to cut, delimb, top and transport a groupof trees for dumping in a stack at a collection point. In contrast tothis, previously known procedures required several pieces of equipmentand several operators to accomplish the same result. Thus, with the treeharvesting apparatus and method of this invention considerable expenseis saved both in machinery and labor over previously known treeharvesting methods.

What is claimed is: 1. Apparatus for delimbing and topping a supportedtree comprising, in combination:

drive means connected to said apparatus for driving said apparatus alongsaid supported tree;

delimber blade means mounted on said apparatus and moveable into and outof engagement with said supported tree to remove all branches from thetree as said apparatus is driven along said tree;

top shear knife means mounted on said apparatus and actuatable to removethe top portion of said tree; latching means carried by said apparatusfor retaining the top shear knife means in an open position;

and means carried by said apparatus for actuating said latching means torelease said top shear knife means into engagement with said tree to topsaid tree upon movement of said apparatus to a predetermined distancealong the length of said tree or in response to closing movement of saiddelimber blade means to a position corresponding to a predetermineddiameter of said tree, whichever of these occurs first.

2. Tree harvesting apparatus comprising, in combination:

a mobile vehicle;

mast means mounted on said mobile vehicle;

grapple means mounted at one end of said mast means and adapted tograsp, sever, and securely hold a standing tree in a position adjacentsaid mast means;

and a delimbing and topping unit mounted for relative movement on saidmast means and including drive means connected to said unit for drivingsaid unit along said mast, a pair of delimber blades mounted on saidunit and moveable into and out of engagement with the tree held by saidgrapple means to remove all branches from the tree as said unit isdriven along said mast, a pair of top shear knives mounted on said unitand actuatable to remove the top portion of said tree, latching meanscarried by said apparatus for retaining the top shear knives in an openposition, and means carried by said unit for actuating said latchingmeans to release said top shear knives into engagement with said tree totop said tree upon movement of said unit to a predetermined distancealong the length of said tree or in response to closing movement of saiddelimber blades to a position corresponding to a predetermined diameterof said tree, whichever of these occurs first.

3. Tree harvesting apparatus comprising, in combination:

a mobile vehicle; mast means mounted on said mobile vehicle and orientedin a substantially horizontal direction;

felling grapple means pivotally mounted at one end of said mast meansand adapted to grasp, sever, and pivot a standing tree to asubstantially horizontal position overlying said mast means;

transfer grapple means fixed to said mast means adjacent said fellinggrapple means and adapted to receive a tree from said felling grapplemeans and securely hold the tree in a substantially horizontal positionoverlying said mast means;

a delimbing and topping unit mounted for relative movement on said mastmeans and including drive means connected to said unit for driving saidunit along said mast, a pair of delimber blades mounted on said unit andmoveable into and out of engagement with the tree held by said transfergrapple means to remove all branches from the tree as said unit isdriven along said mast, a pair of top shear knives mounted on said unitand actuatable to remove the top portion of said tree, latching meanscarried by said apparatus for retaining the top shear knives in an openposition, and means carried by said unit for actuating said latchingmeans to release said top shear knives into engagement with said tree totop said tree upon movement of said unit to a predetermined desireddistance along the length of said tree or in response to closingmovement of said delimber blades to a position corresponding to apredetermined desired diameter of said tree, whichever of these occursfirst;

and collection means attached to said mast means and adapted to receivea number of delimbed and topped trees to be transported with said treeharvesting apparatus.

4. Tree harvesting apparatus as set forth in claim 3 wherein saiddelimbing and topping unit further includes spring biasing means mountedon said unit for normally spring biasing said delimber blade intoengagement with said tree.

5. Tree harvesting apparatus as set forth in claim 4 wherein said springbiasing means for each of said delimber blades comprises, incombination:

a cylindrical housing mounted on said unit;

a delimber blade mounting shaft keyed to one of said delimber blades forrotation therewith, said shaft mounted for rotation at one end to saidunit and at the other end to said cylindrical housing;

a first clutch plate positioned within said cylindrical housing andattached to said shaft for rotation therewith;

a second clutch plate positioned within said cylindrical housingadjacent to said first clutch plate;

said first and second clutch plates having mating grooves thereinforming an annular inclined plane therebetween;

a plurality of spherical balls positioned between said first and secondclutch plates in the grooves therebetween; said balls combining withsaid grooves to translate axial movement of said second clutch rel ativeto said cylindrical housing into rotational movement of said firstclutch plate relative to said cylindrical housing;

a coil spring positioned within said cylindrical housing and attached atone end to said second clutch plate;

and spring actuating means positioned within said cylindrical housingand keyed to said cylindrical housing for axial movement only withinsaid cylindrical housing, said spring actuating means attached to saidcoil spring and adapted to be moved axially within said cylindricalhousing to compress said coil spring toward said second clutch plate tothereby cause axial movement of said second clutch plate relative tosaid cylindrical housing and rotational movement of the first clutchplate, delimber blade shaft, and delimber blade relative to saidcylindrical housing.

6. Tree harvesting apparatus as set forth in claim 4 wherein saiddelimbing and topping unit further includes a counter-balance plateintegral with each of said delimber blades and rotatable therewith, atleast one of said counter-balance plates having a lost motion slotformed therein.

7. Tree harvesting apparatus as set forth in claim 6 wherein said meanscarried by said unit to actuate said latching means includes a pinrestrained for movement within the lost motion slot in one of saidcounterbalance plates and a rod connected at one end to said pin and atthe other end to said latching means for movement with saidcounter-balance plate to actuate said latching means and release saidtop shear knives into engagement with said tree to top said tree inresponse to closing movement of said delimber blades to a positioncorresponding to a predetermined desired diameter of said tree.

8. Tree harvesting apparatus as set forth in claim wherein saiddelimbing and topping unit further includes a counter-balance plateintegral with each of said delimber blades and rotatable therewith, atleast one of said counter-balance plates having a lost motion slotformed therein.

9. Tree harvesting apparatus as set forth in claim 8 wherein said meanscarried by said unit to actuate said latching means includes a pinrestrained for movement within the lost motion slot in one of saidcounterbalance plates and a rod connected at one end to said pin and atthe other end to said latching means for movement with saidcounter-balance plate to actuate said latching means and release saidtop shear knives into engagement with said tree to top said tree inresponse to closing movement of said delimber blades to a positioncorresponding to a predetermined desired diameter of said tree.

10. Tree harvesting apparatus as set forth in claim 3 further includinga first cam means positioned on said mast means at a distance from saidtransfer grapple means corresponding to a predetermined desired lengthof said tree.

1 1. Tree harvesting apparatus as set forth in claim 10 wherein saidmeans carried by said unit to actuate said latching means furtherincludes a lever arm pivotally mounted at one end to said unit, a firstcam follower attached to the free end of said lever arm and adapted toengage and follow said first cam means as said unit passes over thelocation of said first cam means on said mast means, and a connectingarm connected at one end to said lever arm near the free end thereof andat the other end to said latching means for movement with .said leverarm as said first cam follower engages and follows said first cam meansto actuate said latching means and release said top shear knives intoengagement with said tree to top said tree at a predetermined desiredlength of said tree.

12. Tree harvesting apparatus as set forth in claim 7 further includinga first cam means positioned on said mast means at a distance from saidtransfer grapple means corresponding to a predetermined desired lengthof said tree.

13. Tree harvesting apparatus as set forth in claim 12 wherein saidmeans carried by said unit to actuate said latching means furtherincludes a lever arm pivotally mounted at one end to said unit, a firstcam follower attached to the free end of said lever arm and adapted toengage and follow said first cam means as said unit passes over thelocation of said first cam means on said mast means, and a connectingarm connected at one end to said lever arm near the free end thereof andat the other end to said latching means for movement with said lever armas said first cam follower engages and follows said first cam means toactuate said latching means and release said top shear knives intoengagement with said tree to top said tree at a predetermined desiredlength of said tree.

14. Tree harvesting apparatus as set forth in claim 9 further includinga first cam means positioned on said mast means at a distance from saidtransfer grapple means corresponding to a predetermined desired lengthof said tree.

15. Tree harvesting apparatus as set forth in claim 14 wherein saidmeans carried by said unit to actuate said latching means furtherincludes a lever arm pivotally mounted at one end to said unit, a firstcam follower attached to the free end of said lever arm and adapted toengage and follow said first cam means as said unit passes over thelocation of said first cam means on said mast means, and a connectingarm connected at one end to said lever arm near the free end thereof andat the other end to said latching means for movement with said lever armas said first cam follower engages and follows said first cam means toactuate said latching means and release said top shear knives intoengagement with said tree to top said tree at a predetermined desiredlength of said tree.

16. Tree harvesting apparatus as set forth in claim 15 further includinga second cam means positioned on said mast means near said transfergrapple means.

17. Tree harvesting apparatus as set forth in claim 15 wherein saiddelimbing and topping unit further includes opening means carried bysaid unit and engageable by said second cam means to move said top shearknives to an open position for re-engagement by said latching means andto overcome the force of said spring biasing means on said delimberblades to move said delimber arms to an open position upon movement ofsaid unit along said mast means to the location of said second cam meanson said mast means near said transfer grapple means.

18. Tree harvesting apparatus as set forth in claim 17 wherein saidopening means includes a circular actuating plate rotatably mounted tosaid unit, a second cam follower attached to said actuating plate andadapted to engage and follow said second cam means and rotate saidactuating plate upon engagement with said second cam means, a p air ofcables each wrapped around a portion of the circumference of saidactuating plate and attached at one end thereto, said cables each beingattached at their other end to said counter-balance plates for rotatingsaid counter-balance plates and delimber arms to an open position uponengagement of said second cam follower and said second cam means, a topshear opening bar attached to said top shear knives at one end andhaving a lost motion slot therein shear knives to provide uniformopening and closing movement of said top shear knives.

20. Tree harvesting apparatus as set forth in claim 3 wherein saiddelimbing and topping unit further includes opening means carried bysaid unit for moving said top shear knives and said delimber blades toan open position upon movement of said unit on said mast means to aposition near said transfer grapple means. 1F

1. Apparatus for delimbing and topping a supported tree comprising, incombination: drive means connected to said apparatus for driving saidapparatus along said supported tree; delimber blade means mounted onsaid apparatus and moveable into and out of engagement with saidsupported tree to remove all branches from the tree as said apparatus isdriven along said tree; top shear knife means mounted on said apparatusand actuatable to remove the top portion of said tree; latching meanscarried by said apparatus for retaining the top shear knife means in anopen position; and means carried by said apparatus for actuating saidlatching means to release said top shear knife means into engagementwith said tree to top said tree upon movement of said apparatus to apredetermined distance along the length of said tree or in response toclosing movement of said delimber blade means to a positioncorresponding to a predetermined diameter of said tree, whichever ofthese occurs first.
 2. Tree harvesting apparatus comprising, incombination: a mobile vehicle; mast means mounted on said mobilevehicle; grapple means mounted at one end of said mast means and adaptedto grasp, sever, and securely hold a standing tree in a positionadjacent said mast means; and a delimbing and topping unit mounted forrelative movement on said mast means and including drive means connectedto said unit for driving said unit along said mast, a pair of delimberblades mounted on said unit and moveable into and out of engagement withthe tree held by said grapple means to remove all branches from the treeas said unit is driven along said mast, a pair of top shear knivesmounted on said unit and actuatable to remove the top portion of saidtree, latching means carried by said apparatus for retaining the topshear knives in an open position, and means carried by said unit foractuating said latching means to release said top shear knives intoengagement with said tree to top said tree upon moveMent of said unit toa predetermined distance along the length of said tree or in response toclosing movement of said delimber blades to a position corresponding toa predetermined diameter of said tree, whichever of these occurs first.3. Tree harvesting apparatus comprising, in combination: a mobilevehicle; mast means mounted on said mobile vehicle and oriented in asubstantially horizontal direction; felling grapple means pivotallymounted at one end of said mast means and adapted to grasp, sever, andpivot a standing tree to a substantially horizontal position overlyingsaid mast means; transfer grapple means fixed to said mast meansadjacent said felling grapple means and adapted to receive a tree fromsaid felling grapple means and securely hold the tree in a substantiallyhorizontal position overlying said mast means; a delimbing and toppingunit mounted for relative movement on said mast means and includingdrive means connected to said unit for driving said unit along saidmast, a pair of delimber blades mounted on said unit and moveable intoand out of engagement with the tree held by said transfer grapple meansto remove all branches from the tree as said unit is driven along saidmast, a pair of top shear knives mounted on said unit and actuatable toremove the top portion of said tree, latching means carried by saidapparatus for retaining the top shear knives in an open position, andmeans carried by said unit for actuating said latching means to releasesaid top shear knives into engagement with said tree to top said treeupon movement of said unit to a predetermined desired distance along thelength of said tree or in response to closing movement of said delimberblades to a position corresponding to a predetermined desired diameterof said tree, whichever of these occurs first; and collection meansattached to said mast means and adapted to receive a number of delimbedand topped trees to be transported with said tree harvesting apparatus.4. Tree harvesting apparatus as set forth in claim 3 wherein saiddelimbing and topping unit further includes spring biasing means mountedon said unit for normally spring biasing said delimber blade intoengagement with said tree.
 5. Tree harvesting apparatus as set forth inclaim 4 wherein said spring biasing means for each of said delimberblades comprises, in combination: a cylindrical housing mounted on saidunit; a delimber blade mounting shaft keyed to one of said delimberblades for rotation therewith, said shaft mounted for rotation at oneend to said unit and at the other end to said cylindrical housing; afirst clutch plate positioned within said cylindrical housing andattached to said shaft for rotation therewith; a second clutch platepositioned within said cylindrical housing adjacent to said first clutchplate; said first and second clutch plates having mating grooves thereinforming an annular inclined plane therebetween; a plurality of sphericalballs positioned between said first and second clutch plates in thegrooves therebetween; said balls combining with said grooves totranslate axial movement of said second clutch relative to saidcylindrical housing into rotational movement of said first clutch platerelative to said cylindrical housing; a coil spring positioned withinsaid cylindrical housing and attached at one end to said second clutchplate; and spring actuating means positioned within said cylindricalhousing and keyed to said cylindrical housing for axial movement onlywithin said cylindrical housing, said spring actuating means attached tosaid coil spring and adapted to be moved axially within said cylindricalhousing to compress said coil spring toward said second clutch plate tothereby cause axial movement of said second clutch plate relative tosaid cylindrical housing and rotational movement of the first clutchplate, delimber blade shaft, and delimber blade relative to saidcylindrical housing.
 6. TreE harvesting apparatus as set forth in claim4 wherein said delimbing and topping unit further includes acounter-balance plate integral with each of said delimber blades androtatable therewith, at least one of said counter-balance plates havinga lost motion slot formed therein.
 7. Tree harvesting apparatus as setforth in claim 6 wherein said means carried by said unit to actuate saidlatching means includes a pin restrained for movement within the lostmotion slot in one of said counter-balance plates and a rod connected atone end to said pin and at the other end to said latching means formovement with said counter-balance plate to actuate said latching meansand release said top shear knives into engagement with said tree to topsaid tree in response to closing movement of said delimber blades to aposition corresponding to a predetermined desired diameter of said tree.8. Tree harvesting apparatus as set forth in claim 5 wherein saiddelimbing and topping unit further includes a counter-balance plateintegral with each of said delimber blades and rotatable therewith, atleast one of said counter-balance plates having a lost motion slotformed therein.
 9. Tree harvesting apparatus as set forth in claim 8wherein said means carried by said unit to actuate said latching meansincludes a pin restrained for movement within the lost motion slot inone of said counter-balance plates and a rod connected at one end tosaid pin and at the other end to said latching means for movement withsaid counter-balance plate to actuate said latching means and releasesaid top shear knives into engagement with said tree to top said tree inresponse to closing movement of said delimber blades to a positioncorresponding to a predetermined desired diameter of said tree.
 10. Treeharvesting apparatus as set forth in claim 3 further including a firstcam means positioned on said mast means at a distance from said transfergrapple means corresponding to a predetermined desired length of saidtree.
 11. Tree harvesting apparatus as set forth in claim 10 whereinsaid means carried by said unit to actuate said latching means furtherincludes a lever arm pivotally mounted at one end to said unit, a firstcam follower attached to the free end of said lever arm and adapted toengage and follow said first cam means as said unit passes over thelocation of said first cam means on said mast means, and a connectingarm connected at one end to said lever arm near the free end thereof andat the other end to said latching means for movement with said lever armas said first cam follower engages and follows said first cam means toactuate said latching means and release said top shear knives intoengagement with said tree to top said tree at a predetermined desiredlength of said tree.
 12. Tree harvesting apparatus as set forth in claim7 further including a first cam means positioned on said mast means at adistance from said transfer grapple means corresponding to apredetermined desired length of said tree.
 13. Tree harvesting apparatusas set forth in claim 12 wherein said means carried by said unit toactuate said latching means further includes a lever arm pivotallymounted at one end to said unit, a first cam follower attached to thefree end of said lever arm and adapted to engage and follow said firstcam means as said unit passes over the location of said first cam meanson said mast means, and a connecting arm connected at one end to saidlever arm near the free end thereof and at the other end to saidlatching means for movement with said lever arm as said first camfollower engages and follows said first cam means to actuate saidlatching means and release said top shear knives into engagement withsaid tree to top said tree at a predetermined desired length of saidtree.
 14. Tree harvesting apparatus as set forth in claim 9 furtherincluding a first cam means positioned on said mast means at a distancefrom said transfer grapple means corresponding to a predetermineddEsired length of said tree.
 15. Tree harvesting apparatus as set forthin claim 14 wherein said means carried by said unit to actuate saidlatching means further includes a lever arm pivotally mounted at one endto said unit, a first cam follower attached to the free end of saidlever arm and adapted to engage and follow said first cam means as saidunit passes over the location of said first cam means on said mastmeans, and a connecting arm connected at one end to said lever arm nearthe free end thereof and at the other end to said latching means formovement with said lever arm as said first cam follower engages andfollows said first cam means to actuate said latching means and releasesaid top shear knives into engagement with said tree to top said tree ata predetermined desired length of said tree.
 16. Tree harvestingapparatus as set forth in claim 15 further including a second cam meanspositioned on said mast means near said transfer grapple means.
 17. Treeharvesting apparatus as set forth in claim 15 wherein said delimbing andtopping unit further includes opening means carried by said unit andengageable by said second cam means to move said top shear knives to anopen position for re-engagement by said latching means and to overcomethe force of said spring biasing means on said delimber blades to movesaid delimber arms to an open position upon movement of said unit alongsaid mast means to the location of said second cam means on said mastmeans near said transfer grapple means.
 18. Tree harvesting apparatus asset forth in claim 17 wherein said opening means includes a circularactuating plate rotatably mounted to said unit, a second cam followerattached to said actuating plate and adapted to engage and follow saidsecond cam means and rotate said actuating plate upon engagement withsaid second cam means, a pair of cables each wrapped around a portion ofthe circumference of said actuating plate and attached at one endthereto, said cables each being attached at their other end to saidcounter-balance plates for rotating said counter-balance plates anddelimber arms to an open position upon engagement of said second camfollower and said second cam means, a top shear opening bar attached tosaid top shear knives at one end and having a lost motion slot thereinat its other end, and a pin positioned for movement within said lostmotion slot in top shear opening bar and attached to said actuatingplate for rotation therewith, said top shear opening bar opening saidtop shear knives upon engagement of said second cam follower with saidsecond cam means.
 19. Tree harvesting apparatus as set forth in claim 18wherein said delimbing and topping unit further includes a pair ofmating timing gears carried by said top shear knives to provide uniformopening and closing movement of said top shear knives.
 20. Treeharvesting apparatus as set forth in claim 3 wherein said delimbing andtopping unit further includes opening means carried by said unit formoving said top shear knives and said delimber blades to an openposition upon movement of said unit on said mast means to a positionnear said transfer grapple means.